George Cole--
That's an interesting view, but I don't think currency trading is guided, at the moment, by supply and demand. It seems that currencies are being bought and sold on prospects for economic growth, so I would actually expect a rate cut to strengthen the dollar, rather than weaken it -- unless forex traders interpret a rate cut as a sign that U.S. growth is failing and believe that the Fed action won't be able to save the economy. Market psychology right now is very different from the "rationality" assumed in our economics textbooks.